Improvement in sperm functional competence through modified low‐dose packaging in French mini straws of bull semen

Abstract

To achieve the targeted artificial insemination coverage with the current rate of semen production, without affecting the conception rate, it needs to reduce the number of spermatozoa per insemination dose in India as per international practice. Therefore, this study was planned to perform different levels of semen dilution, compare in vitro post-thaw semen quality and develop a modified low-dose semen packaging method in French mini straw to minimise semen dilution effect. Sixteen ejaculates were collected from Karan Fries bulls (n = 4). The mean percentage post-thaw motility, viability, membrane integrity, acrosome integrity, lipid peroxidation and capacitation status were estimated as post-thaw sperm function assays in semen sample diluted to 20, 15, 10 and 5 million spermatozoa per 0.25 ml and filled in the French mini straw by conventional packaging. No significant (p > .05) difference in post-thaw sperm quality was observed between 15 and 20 million doses; however, below 15 million sperm quality get reduced. There was no significant difference in post-thaw semen quality traits between 20 million conventional packaging and 5 million spermatozoa/dose in modified packaging. In conclusions, the modified packaging is a very effective method for low-dose cryopreservation with acceptable post-thaw semen quality.

Supplementing extender with anandamide enhances quality of low sperm doses during cryopreservation in bulls

“…This was supported by other findings, which revealed that higher dilutions of semen had negative effect on capacitation and acrosome status of spermatozoa (Prathalingam, Holt, Revell, Jones, & Watson, 2006;Schembri, Major, Suttie, Maxwell, & Evans, 2002). Previous study had revealed that during cryopreservation, the proportion of acrosome intact sperm decreased by about 31%, and the proportion of noncapacitated spermatozoa reduced by about 27%, when semen of crossbred bulls was diluted from 20 million to 5 million spermatozoa (Karan et al, 2018). The reduced percentage of capacitated spermatozoa in anandamide-treated semen might be due to anandamides decapacitating nature (Kumar et al, 2018;Schuel et al, 2002).…”

“…We observed dilution drastically reduced post-thaw sperm quality in terms of reduced proportion of motile spermatozoa, live spermatozoa and increased proportions of dead spermatozoa, acrosome-reacted spermatozoa and capacitated spermatozoa particularly below 10 million spermatozoa in Sahiwal bulls. These reductions in these sperm quality parameters were in line with Karan et al (2018), who observed higher semen dilutions reduced (p < .05)…”

“…Dilution is thought to remove certain sperm coating proteins, reduces seminal natural antioxidant profile and other necessary constituents present in the seminal plasma, that are required for maintaining functional attributes of spermatozoa (Maxwell, Landers, & Evans, 1995). The higher dilutions of semen to low sperm concentrations result in reduced postthaw motility (Karan et al, 2018;Lone et al, 2020), live spermatozoa (Garner et al, 1997;Maxwell & Johnson, 1997), acrosomal integrity and membrane integrity (Karan et al, 2018;Lone et al, 2020). The alterations in these seminal attributes due to higher dilutions may vary from bull to bull, breed to breed and even among ejaculates of the same bull.…”

“…anandamide, bull, extender, low dose, sperm quality however, higher dilutions of semen for producing numerous numbers of low sperm doses result in reduced post-thaw sperm motility (Karan et al, 2018), live sperm count (Garner, Thomas, & Allen, 1997;Maxwell & Johnson, 1997), acrosomal integrity and membrane integrity (Karan et al, 2018;Lone et al, 2020). These alterations in the sperm attributes due to higher dilutions may vary from bull to bull, breed to breed and even among ejaculates of the same bull.…”

“…The seminal plasma contains certain decapacitating factors, that prevent spermatozoa from capacitation; at higher dilutions, the level of seminal plasma is reduced which compromises sperm quality in terms of reduction in sperm motility, sperm viability and membrane integrity and also leads to capacitation-like alterations in spermatozoa during cryopreservation (Karan et al, 2018;Maxwell & Johnson, 1997). It has been revealed that incubating spermatozoa with anandamide prior to their cryopreservation improves sperm quality in terms of increase in proportion of motile spermatozoa, live spermatozoa, membrane intact spermatozoa and reduced capacitated sperm post-thaw (Kumar et al, 2018).…”